The present invention relates to certain improvements in a tire press, loader and method of the type shown in U.S. Pat. No. 4,447,385 to Blosser et al dated May 8, 1984. Such prior patent discloses a top loading press, i.e. one in which the green tire is first centered and loaded into the top mold section, and then into the bottom mold section, as the press closes and the shaping bladder is inserted. Such sequence, of course, permits gravity to assist in proper centering and loading.
Such prior patent discloses a loader/unloader which comprises an inflatable bladder type ring adapted to grip the tread section of the uncured or cured tire for loading or unloading. This, of course, leaves the beads of the tire free to be controlled by the press. While such loader/unloader mechanism has proven quite acceptable, it nonetheless has certain drawbacks. For example, the loader chuck is difficult as a whole to center with respect to the centerline of the press. Perhaps more importantly, the chuck is limited in the range of tire sizes it can handle, thus requiring a replacement chuck if significant changes in tire sizes are made.
Also, such prior patent illustrates two embodiments of a chuck in the top mold section adapted to engage and grip the top bead of the uncured tire held by the loader and lift it centered for subsequent proper seating engagement with the bead ring of the top mold section. One embodiment utilizes a bladder chuck, while the other utilizes an essentially horizontal plate type chuck such as shown in prior U.S. Pat. No. 3,530,533 to Turk et al. The bladder type chuck, because of its yielding and flexible nature and construction has not proven totally acceptable with regard to centering of the top bead in the upper bead ring. It also has limited service life. The plate type chuck completely mechanically and unyieldingly controlled also has problems with regard to precise centering.
Also, problems may occur in the tire stripping process as shown in such prior patent in that the cured tire may not remain on the vertically movable bottom bead ring. To correct this problem as well as to facilitate the stripping of the bladder into its well or can on which the bottom bead ring may be mounted, it is desirable that the bladder act to hold the bottom bead of the cured tire as long as possible on the bottom bead ring, while nevertheless facilitating the removal of the shaping bladder from the cured tire. This then ensures the position of the cured tire for proper unloading, whether it be by the loader/unloader or by some other unloader mechanism.